SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aac1d24948bf86c8e2345c58256db936262319aafb2fbfb3ea6d474552506ed7' 
  AND token = 'ywKReZbocOpyfc7h6Uij0WYzfpDrixGXVsa2bQqLB2I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}